摘要
普通负压式水银张力计最小读数 1 mm汞柱 ,即最小读数为 1 3 .6mm水柱。改进后负压式复合张力计读数更精确 ,最小读数为 1 .0 mm水柱 ,提高精确度 1 3 .6倍 ,使用其测定土壤水势更准确。田间条件测定土壤水势改以往普通负压式水银张力计一点测定为改进后负压式复合张力计两点测定 ,并能直接反映田间两点水势差异情况 ,判断田间土壤水分运动趋势。它使研究温度对土壤水势影响更方便 ,改装后负压式复合张力计对温度升降造成水势变化是通过 U形管式黄液压力计读数反映的 ,所以较准确反映温度对水势影响 ,因而测得结果更接近田间土壤水势。另外 ,改装后负压式复合张力计能准确测定土壤水势 ,通过称重计算出一定时间经过一段距离和横断面土壤水分运动而散失水量 ,从而求得在稳态流条件下土壤非饱和导水率 。
The least number can be seen is 1.00 mm Hg column (13.6 mm water column) in Soil tension meter with negative pressure mercury. Soil complex tension meter′s the least number is 1.00 mm water column by improving on soil tension meter with negative pressure mercury, the sensitivity of complex tension meter increase 13.6 times than tension meter. The flow of soil water was determined in field by two sites replaced one site, the result can directly show difference between two assaying sites, and judge trend of soil water movement. Meantime soil complex tension meter is good and exactness at temperature dependence.Soil complex tension meter can apply some parameters of soil water movement although exact assaying difference between soil flow of water, for example soil dissipating amount, soil non saturation conductivity.
出处
《西北农业学报》
CAS
CSCD
2002年第2期29-33,共5页
Acta Agriculturae Boreali-occidentalis Sinica
基金
国家自然科学基金资助项目 (4 8970 0 3 5 )
关键词
负压式复合张力计
土壤水势
测定
土壤非饱和导水率
土壤水分
Negative pressure complex tension meter
Soil water potential
Precision
Temperature
Water transmitting rate
